Method of simultaneously beaming and electroplating wires



Aug. 24, 1948. R. CLPlERCE METHOD OF SIMULTANEOUSLY BEAMING AND ELECTROPLATING WIRES 1705 2 fl w Filed Nov. 11, 1944 Patented Aug. 24, 1948 METHGD F SIMULTANEOUSLY BEAMING ELECTROPLATJNG WIRES Robert. C. Bierce, Niles, Mich, assignorto National-St'andard'. Company, a. corporation. of.

Michigan Application N ovemberi 11, 1944; Serial No.' 562,953:

2 Claims.

This, invention relatesto. a. plated wire and. more particularly. to abeame'diwirei oifine" diameter and low elastic limit.

Beaming comprises simultaneous windin of 'a plurality of wiresupon a common spool. Wire-is customarily beamed for numerous purposes but particularly wherejit is. to be braidedor similarly handled.

The wire which is to go on thebeamingspooll is customarily'stored' and transported on spools on which the wire" is wounid' in'a plurality of overlapping courses, each extending from one end of the spool; to the other; In. handling very fine wires, particularly of metal" such as copper; the mere transfer from one spool to ano-theris a matter of some difficulty and islikely'to lead to considerable breakage. For example,v an. annealed copper-wire havingqa' diameter of 0.005" inch and having an elastic limit" of 12,000 lbs. per square inch, will stretch heyond' its elastic limit if the; tension upon it'exceed's 1b. Even with a similar wire of 0;020'inch' diameter, th tensioncannot exceed 45 lbs. The present invention pro.- duces a beamed? product consisting of sucha small wire havingian electroplated 'coating'thereon and not stretched beyond its elastic limit after or during application of the coating;

This is accomplished by mounting" the" take-ofi spools insuch manner as simultaneously to feed wiresat a'predeterminedl'evel, passing the wires under tension below'their deforming tension in a catena'rypath of extremely small depth-tea takeup spool or drum. The-wires may in theirpath be permitted to-fall; toth'e extent of the" depth of" the catenary, int'o one or more-bathswhich preferably include acleaning bath, a pickling bath, a-' plating bath; and one or more washing baths. Plating ispreferably 'by" electro-d'eposition. It is of course impracticable toemploy solid contacts within the catenary when dealing with wires of" such.- small. strength. Current is. therefore, passed; through the wires 'by contacts which iii-- cludeone or more of thebath's and one of the spools; preferably a power driven take -up spool or-drum';

This invention is ansimpro-vement upon the de-- velopments set forth in the: co-p'ending' applications of ClareLuke; SerialNo'. 558.697, filed October 14,1944; and Serial No. 560.513; filed- October 26,- 1944. In the presentdevelopment" the beaming process is combined withthe Luke meth- 0d of treating. Because of this combination it has been possible to'elimi'nat'e a separatebeam ing operation: which has heretofore; always been required and at the same time the permissibletensionupon the wire was raised because of exerting this tensionupon a group of wires rather than each wire separately. It should be. observed, however, that the permissible tension does not increase arithmetically as the number of wires increases because of the fact that at certain.

stages of the process one or more of the wires may from time to time develop slack. On the whole,

however,. a group of very fine wires which are passed simultaneously through the baths to a common spool unite into a body having increased. strength. They may even be associated insuch a. body through the plating bath, but for some types.

of platin and for some sizes of wires a small separating comb may be inserted in the plating bath.

to separate the wires during their passage therethrough.

The invention is illustrated in the drawings in which Fig- 1" is a side elevation of an apparatus suitable for practicing the invention; Fig. 2 is a plan view; Fig. 3'is an enlarged sectional side elevation showing in detail the method of suspension ofthe wire catenary in two of the baths; Fig. 4 is a diagrammatic enlargedview of the wire; and Fig- 5'is.a transverse end elevation. of a modified iorm'ofoverflow.

The apparatus comprises a suitable mounting 20 upon which a plurality of let-off spools 2| are mounted. A series of tensioning and spacing members 22' are provided adjacent the spool to maintain the wires 25 at substantially a predetermi'ned vertical position. The wires pass in a bod'ythrough a series of baths which will be later described to a power driven capstan [0 around which the wires are wrapped several times and from which they are passed to a beaming spool 23. It will be noted that between the spacing or' tensioning'devices 22 and the point of contact with the capstan I0 the wires are suspended in a, catenary of very small depth. With 0.005 inch annealed copper wire the catenary should not be deeper than approximately /2 inch and is preferably about /i inch. For 0.020 wire the depth of the catenary may be somewhat greater,

The series of baths comprises an alkali cleaning bath 2 preferably containing an alkali cyanide solution; a cold water rinse 3, an acid pickle bath 4, a water wash 5, a plating bath 6, a cold water wash 1, and a hot water wash 8. Each of the-baths is constantly supplied with fluid which overflows at the edges of the baths as shown in Figure 3'. This'overflow is, except in the case of the-cold'washwater, recycled by means of pumps H. The surface tension of the liquid in each bath form's an invertedlmeniscus 12 at the over-- and the capstan itself (or the take-up'spool 23') is negatively charged. Electrons, therefore enter nd thef the wires through the cleaningbath} M I capstan Hi and are withdrawn through'the plating bath and the electrodes l5. Viewed in the conventional manner, current'is'introduc'ed into the wires in the plating bath and passes out of them in a divided current, part to the electrodes I 4, and part to the capstan [0. Conventional voltage regulators are employed to divide the' c r; rent equally between these two paths.

1'Ihewires may be withdrawn from the let-'ofl" spool ata speed of 400ft. to 500 f t. per'minute. A suitable total tension is less than ,4 lb. The cleaning bath is designed to remove saponifiable impuritiesand suitably is ,an alkali cyanide, for exampleone containing 2 oz. of sodium cyanide per gallon. It is preferably heated to a temperature of the order .of 140 F., as, for example, by steam ooils,9.. Overflow liquid is recycled by the pump I i beneath the surface of the bath, it being introduced near the bottom. An air jet is havinga smallopening immediately above the wire and directed vertically downward removes cleaning liquid carried from the bath by the wires. Anenlarged jet is shown in Figure 3. .The amount of liquidcarriedfrom a bathby a small wire is extremely. great and losses because of this would be sllfficlent to render the process unduly expensive, if theliquid were permitted to be lost. In conventional platingbaths the liquid is removed by wipespf cloth or other material. but in the present system suchmethods cannot be employed because of the tension necessarilyimposed. The air blast satisfactorily removes the liquid from small wires and thewires feel dry to the touch after passing through the air. Similar air jets are provided after each bath. A single jetwill take care of all of the wires under normal circum-. stances... .-In each case the jet is within the area inch. At 500 ft. per minute, and 500 amperes per square foot, the wire will acquire this coating in 9 feet of travel. The preferred bath has about this length.

A comb 30 may be provided at the entrance to the plating bath to spread the wires slightly. A similar comb maybe supplied atthe end of the bath. Normally, however, plating may be accomplished without the combs, and even where a comb is desirable, a single comb within the bath 'As shown in the drawing, the bottom l5 of the bath, which is of metal and serves as the electrode, isslop'ed downwardly "from the center in each direction. The amount of this slope is such as to equalize the voltage drop through the solution.

' It'must of course be varied with variations in the sizeof the wire and, for that reason, is preferably hinged at l5a to permit adjustment.

The platingv fluid isheated in the sumpby steam coils 9a preferablyto a temperaturelin.

the neighborhood of 140 F. ..The liquid is circulated by a pump lib and reintroduced at the bottom of the tank 6. y

The wires pa'ss i'rom the plating bath under another air' jet [6' through the overflow of. the

cold water wash 7, under another air jet- 16, through the overflow or the hot water wash-8, under. another air jet I 6 and to the capstan Ill.

The hot water Wash ismaintained at a temperature aroundlQO" F. bysteam coils 9 in the sump.

Overflow is circulated to the bottom of the tank by the pump Hc. This hot water bath serves 1 to assist the final air jet [6 byheatingthe wire.

to a point where any remnant orltrace of water.

is evaporated. The capstan i0 is of conventionaltapered shape. and is sospaced that its take-up level is substans .tially the .same as the level produced .by the. ten-v bounded by the sump below the bath. Each bath, 1

hydrochloric which is ordinary commercal hy-v drochloric diluted with from 1 to 4 parts oiwater. Overflow acid is recirculatedby the pump Ho.

The edges of this tank; as is the case with all of the other tanks, should have substantially the same level so that the overflows in 'alljcases are within thecatenary formed by. the wire 25. The wires, after, cleansingand neutralization inthis bath, pass under another air jet l6 and into the water wash5, into another jet l6 and into the plating bathin r 7 I For-tin-plating a fluoride tin-bath of conventional-composition may-beemployed; A suitable amperage is 500 per square foot but this may be varied to as low as 20 or-ashigh as 1800: The amount'of plating required for use in electric wiring 15111017 great, generally being about 0.0.0002

sioning and spacing devices 22. The. capstanis driven by a motor at apredeterminedspeedand the wire then passes to the spool 23 -which is driven in conventional manner by a slipping beltunder constant tension so that there is no slac k in the wire or anyfsuperimposed-tension beyond the desired amount. t.

It will beobserved that the Wires 25 are'suspended in a catenary of small depth, which cate nary is constantlychanging as the wire advances and which maintains its shape. Thev catenary passes through the overflow of each of the baths, all of-its contact with the liquids being confined to a layer of liquid having the depth of the catenary.- As'already stated, it is preferred to use a c-atenary having a depth I of approximately 4" inch even over a space of approximately feet;

Make-up water issupplied to the cold water tanksinany suitable fashion, as from overhead pipes l8. I

The product produced by the herein described. method is characterized by the fact that all of the plated metal occupies the same position with respect to underlying metal and to the center Of the wire which it occupied at the time it was-d'e:

posited. If I it were attempted to electroplat'e Wiresofl-the type here described byordinary methods; the wire'would stretches much-as 40:- of its lengthso that deposited metal'would be displaced longitudinally and vertically with What I claim as new, and desire to secure by Letters Patent, is:

1. The method of simultaneously beaming and electroplating a plurality of wires of low elastic limit and small diameter which comprises passing a plurality of separate Wires from separate let- 01? devices simultaneously through a series of baths including a plating bath, passing an electric current through the wires whereby a thin layer of plated metal is deposited thereon from the plating bath, the wires being under a common tension during plating but bein laterally spaced in the plating bath and the wires being suspended throughout substantially their entire course in a catenary of small depth in which the Wires form a single body wherein the Wires are close together throughout substantially all of said catenary except within the plating bath, and then beaming the Wires upon a take-up device connected by the wires to the let-ofi devices.

2. The method as set forth in claim 1 in which the entrance of the wires to and the exit of the wires from each bath is through an overflow thereof.

ROBERT C. PIERCE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 242,813 Chinnock June 14, 1881 1,068,412 Chubb et al July 29, 1913 1,698,512 Robbins Jan. 8, 1929 2,089,817 Stutsman Aug. 10, 1937 2,093,238 Domm Sept. 14, 1937 FOREIGN PATENTS Number Country Date 19,586 Great Britain 1890 308,649 Great Britain June 25, 1930 495,907 Great Britain Nov. 21, 1930 

